Successful server virtualization deployments lead many IT managers to believe desktop virtualization would provide the same benefits. While that is partly true, companies need to be aware of how the two technologies differ, industry experts caution.
"Desktop virtualization is a very different beast and should not be treated as simple enhancements to the server strategy," says Natalie Lambert, principal analyst at Forrester Research. "The drivers are entirely different and the environment will present new challenges to those experienced with server virtualization."
For instance, desktop virtualization doesn't offer the near-immediate cost benefits many cite with virtual server rollouts. And while virtual servers present new security and management challenges, many argue that in the desktop realm, virtualization improves security and manageability for IT departments. In addition, the sheer numbers involved can be strikingly different.
"IT managers could be taking on 500 virtual servers, and that is a lot, but it is nothing compared to 10,000 desktops," Lambert says.
According to industry experts and IT pros, there are some similarities and many differences between virtual servers and virtual desktops. Here we highlight key factors that could help avoid major headaches when moving virtualization to the desktop.
Most IT departments at enterprise companies have exponentially more desktops to support than servers, virtual or otherwise. The sheer volume of desktops should be one of the first criteria IT managers consider when making a move to a virtual platform.
With more than one billion PCs in the world, there's a huge opportunity for virtualization, but "all the requirements of the PC world need to be maintained as you migrate into the data center," says Mark Margevicius, vice president and research director at Gartner. "The desktop realm represents a lot more moving parts, considering all the uniqueness that happens on a PC needs to be maintained."
Server virtualization teams are unlikely to be responsible for the desktop infrastructure, beyond the servers that host the virtualization platforms. That means desktop groups need to rethink patch management, software distribution and other functions when applying them to a centralized system rather than a slew of disparate desktops.
"Desktop teams know how to manage 100,000 machines so the practices and policies are completely different. In the virtual realm the desktops come back to the server environment but cannot be thought of in the same terms," Forrester's Lambert says.
For Jake Seitz, expanding his company's VMware server virtualization deployment to include desktops was driven by compliance requirements and a move away from supporting desktop hardware. The enterprise architect at The First American Corp. in Santa Ana, Calif., says his group may be supporting less desktop hardware, but now they are responsible for maintaining "all these unique virtual machines." With 22,000 desktops, Seitz says the plan is to migrate 3,000 to 4,000 per year as hardware comes off its lease or as it fails - a plan that will help his team stay on top of the new virtual environment as well.
"The desktop has its own challenges, including the uniqueness of images personalized by end users. With a 'patch once and push many' approach, the risk of breaking software goes up exponentially," Seitz says. "We have one-off machines in legal or finance, for instance, and we patch them ad hoc as needed. We realize we can't do desktops in a big bang move; it has to be an incremental move."
Double the cost, half the ROI
While server virtualization virtually guarantees a speedy ROI, desktop virtualization can be cost-prohibitive to start and deliver a somewhat less immediate and difficult-to-quantify return on the substantial investment.
Analysts estimate choosing virtual desktops can cost 150% to 250% more than traditional PCs -- and that's just for the direct cost of acquiring the technology. Savvy IT managers realize when pricing out a project they need to also calculate indirect costs.
"Desktop virtualization is a lot like hybrid cars. No one disputes the value and they love the idea, but it is just too expensive to write a check and pay a lot when the traditional version is cheaper and already paid for," Gartner's Margevicius says.
Yet for some organizations the benefits are enough to warrant the investment. For Kevin Nolan, the potential cost, time and labor savings associated with virtual desktops is driving his organization to evaluate the technology. Nolan, manager of systems engineering at Mohawk Industries in Calhoun, Ga., says his company is expanding their use of virtualization technology beyond the 500 VMware virtual servers his group supports. Nolan, who will be speaking at this month's Network World IT Roadmap Atlanta, says adopting virtual desktops would enable his company to extend the refresh cycle on PCs.
"If you have a virtual desktop, you can stretch hardware for more like five or six years, rather than the standard three-year PC refresh cycle," Nolan says. "With a lot less hardware, there are a lot fewer opportunities to break and have to fix machines."
Considering the cost, Nolan says his desktop and server team are working together to evaluate several vendors, including VMware and Citrix. Nolan realizes the desktop realm requires expertise in managing multiple PCs, which Citrix has mastered, but because the technology will reside in the data center and involve the server group, VMware might be a better option.
Analysts say customers could realize price cuts if they did add desktop technology from their virtual server vendor. "Definitely, the more customers buy from one vendor, the more discounts they will receive and the lower the cost per seat could be," Forrester's Lambert says.